> "insert system disk"
means that the Drive that your Computer is trying to boot from does not have a Boot Sector that is active.
Either the Boot Sector was never written, corrupted, or is not set as active. Which ever Drive was your "C:" Drive is what you must boot from.
Look in your BIOS to ensure you are booting from the correct Drive. Try booting your OS Disks from your CDROM to see if you can even boot.